The invention concerns a method to produce a layer electrode for electrochemical components, whereby a layer is connected with a metal. Furthermore, the invention concerns a layer electrode for electrochemical components.
From the printed publication EP 0 786 142, electrochemical components are known in the form of electrochemical double-layer capacitors in which carbon layers are used as layer electrodes. In order to be able to contact the carbon of the carbon fabric with an aluminum electrode, the carbon fabric is first coated with a liquid or molten aluminum by means of an arc method. It is thereby achieved that the aluminum penetrates as deep as possible into the fibers of the carbon fabric, whereby a good electrical contact can be produced.
However, this method has the disadvantage that the hot aluminum easily oxidizes in the air and, due to the aluminum oxide layer thereby ensuing, the electrical contact resistance between the layer and the aluminum metal is increased.
Furthermore, the known method to produce a layer electrode has the disadvantage that the arc method requires a high mechanical stability of the layer in order to prevent a tear in the layer. In order to achieve the lowest ohmic resistance between the carbon material and the material discharging or, respectively, supplying current in an electrochemical double-layer capacitor, a large-surface direct contact must be generated between the carbon material and the metal.
A high mechanical stability of the layer means that the layer must be implemented with a relatively large thickness, whereby the area available for the contact with a metal electrode is reduced, which results in an increase of the ohmic resistance of the capacitor. Moreover, stable carbon layers require the use of expensive, stable fiber materials, which means increased raw material costs.
In the further course of the production, a coated layer is positioned on the top or, respectively, underside of an aluminum film. This aluminum film serves as a discharge electrode for the capacitor. This arrangement from a plurality of parts (film and layers) must be manipulated without shifting in the assembly of a capacitor winding, in order to prevent short circuits on the edge of the film as well as a damage of the carbon layers.
Furthermore, the known method has the disadvantage that it requires a plurality of individual work steps. The aluminum introduced into the layer via the arc method increases the layer thickness of the layer, whereby the volume utilization of the of the capacitor is worsened.